BlueLab Guardian Monitor



The Bluelab Guardian Monitor provides 24-hour continuous reading for pH, conductivity (EC/ppm 700/TDS/CF) and temperature within a nutrient solution. Optimizing these critical parameters through a plants' growing phase helps ensure a successful crop.

Designed for indoor use, the Guardian Monitor can be mounted on a wall or hung on a support bar. Set up your reservoir, place the pH and conductivity probes in the solution, then adjust and glance! Simply set high and low alarm states – if the solution moves away from the ideal range, the display flashes. A quick look at the monitor will let you know when your nutrient solution needs adjusting.


  • Simple and effective reservoir monitor, water-resistant design.
  • No calibration required for conductivity and temperature.
  • Non-volatile memory to retain settings even in the event of power loss.

More Info

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BlueLab Guardian Monitor

In just one glance the Guardian Monitor measures all three critical parameters to successful growth; pH, conductivity and temperature.

Seasonal changes, sunlight hours, wind, inherent plant growth, from vegetative to fruiting, are all influencing factors to plant growth success. More importantly, these parameters change the plant’s uptake and need of water and specific nutrient elements. The Bluelab Guardian is a constant indicator of the desired levels of EC, pH, and temperature, enabling the grower to optimize these parameters as the crop progresses through each growing phase.

The Guardian removes the complexity of how each parameter relies on each other for outstanding growth. This innovative monitor is a new method to help guard the success of your crops with immediate and accurate results. A flashing display lets you know if one parameter moves away from the ideal, allowing you to make the required adjustments quickly and effectively.

Main Features:

  • Adjustable display brightness
  • Large easy to read displays
  • ‘Plant Safe’ green LED display
  • Selectable values for conductivity and temperature
  • Simple push button pH calibration
  • No calibration required for conductivity and temperature
  • Silent alarm for both high and low settings
  • Settings retained when power lost (non-volatile memory)
  • Automatic temperature compensation
  • International power supply
  • Water resistant design
  • The Conductivity and temperature does not require calibration, but the conductivity probe must be cleaned at least once a month to ensure accurate readings. Here are the conductivity cleaning instructions for the conductivity probe.
  • 2 year guarantee for Bluelab Guardian Monitor, 6 month guarantee for Bluelab pH Probe

The pH of the Guardian does require calibration and the Monitor will let you know that calibration is due by flashing the 7 & 4/10 green LEDs every 30 days. The probe should also be cleaned and calibrated at least once a month. Here are the pH cleaning instructions for the pH Probe. Calibration instructions are found in the instruction manual.


Weight 3 lbs
Dimensions 8.75 × 5.25 × 3.75 in

Probe Type

Product Category

Controllers & Meters




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